For a movable contact used in a key switch, a thin metal plate contact has been commonly used. Exemplary thin metal plate contact is made such that
a thin plate such a nickel silver plate and phosphor bronze plate is plated with nickel and then with gold,
bonded with rubber,
and then punched out into a prescribed shape.
On the other hand, in parallel with the thin metal plate contact, another contact has been disclosed (for example, patent literatures 1, 2 and 3), in which a metal wire, metal ribbon or metal mesh is embedded on a surface of a key top. In the above mentioned thin metal plate contact, since the contact surface is flat and has little flexibility, when dust is attached on the other contact surface or the other contact surface has irregularity, the flat contact surface of the thin metal plate contact may come in contact with the other contact surface in an angled posture because the dust or irregularity obstructs the direct contact. In this case, sufficient conduction cannot be obtained, causing contact failure. On the contrary, the contact embedded with a metal wire, metal ribbon or metal mesh forms a conductive uneven surface so as to come in contact with the other contact surface with a number of contact points and thereby to obtain easy contact. However, the proposal has not been given to prevent the cut edge surface of the plated metal mesh from rusting and to improve the operation for bonding the contact to a key top.
Patent literature 1: Unexamined Japanese Utility Model Publication S57-109532,
Patent literature 2: Unexamined Japanese Utility Model Publication 562-54433 and
Patent literature 2: Unexamined Japanese Patent Publication 2004-342539.